Simulated virtual citizen, displayed abstracted as coloured circles, walk through the streets and greet each others by day, exchanging each others colours.
The colours of those who communicate mix. Groups emerge.
At night, the citizens go home (everyone got assigned one per RNG) and regenerate their own colour there.
The recipient can watch the simulation run on its own or take control over one of the citizens.
A little 3D engine for the Linux terminal can connect to the program as client and display the houses from the ego-perspective of one of the citizens (with citizen-selection and minimap functions).